postgres.git / summary / log / commit / refs

commit    dc02c7bca4dccf7de278cdc6b3325a829e75b252
Author:   Robert Haas <rhaas@postgresql.org>
Date:     Wed Mar 22 18:42:03 2017 +0000

    Fix wrong costing of Sort under Gather Merge.
    
    There's no mechanism for such a sort to become a top-N sort, so we
    should pass -1 rather than limit_tuples to cost_sort().
    
    Rushabh Lathia, per a report from Mithun Cy
    
    Discussion: http://postgr.es/m/CAGPqQf1akRcSgC9=6iwx=sEPap9UvPpHJLzg8_N+OuHdb6fL+g@mail.gmail.com


 src/backend/optimizer/plan/planner.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/src/backend/optimizer/plan/planner.c b/src/backend/optimizer/plan/planner.c
index cbdea1f5378..68d74cb4324 100644
--- a/src/backend/optimizer/plan/planner.c
+++ b/src/backend/optimizer/plan/planner.c
@@ -4416,7 +4416,7 @@ create_ordered_paths(PlannerInfo *root,
 											 ordered_rel,
 											 cheapest_partial_path,
 											 root->sort_pathkeys,
-											 limit_tuples);
+											 -1.0);
 
 			total_groups = cheapest_partial_path->rows *
 				cheapest_partial_path->parallel_workers;


[parent: 6b76f1bb58f5]